Thermal Flashlight

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A "Thermal Flashlight" is a DIY device which lets you do a kind of "light painting" -- thermal photography. It produces a colored "heat map" overlaid directly onto a photo of a room. This is the simplest, cheapest, and to date, most effective way we have developed of measuring heat leaks or cool leaks indoors and outdoors. Simply put, the "flashlight" puts out redder light if it's pointed at something hot (default 75 deg F or more) and bluer light if it's pointed at something cold *(default 60 deg F or less).

Parts

The Melexis MLX90614 digital thermometer used in this kit can be found in a few places, at different price points:

Assembly

There are a few versions of the thermal flashlight:

Questions

Title	Author	Updated	Likes	Comments
dealing with patents: Black & Decker and the Thermal Flashlight	@mathew	almost 10 years ago	5	6

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Activities

Purpose	Category	Status	Author	Time	Difficulty	Replications
Common-anode LED thermal flashlight casing and circuit diagram	-	-	@lmc6399group	-	-	0 replications: Try it »
Build a simple Thermal Flashlight	-	-	@warren	-	-	26 replications: Try it »
Thermal Flashlight Using MLX90614 IR Evaluation Board From Sparkfun	-	-	@ajawitz	-	-	0 replications: Try it »
Thermal flashlight: data collection in Holyrood, NL	-	-	@ckenny	-	-	0 replications: Try it »
Visualight board for Thermal Flashlights	-	-	@warren	-	-	0 replications: Try it »
Thermal Flashlight from hacked, off-the-shelf Pocket IR Thermometer	-	-	@ajawitz	-	-	0 replications: Try it »
Thermal Imaging: Heat Insulation Comparison	-	-	@brachium	-	-	0 replications: Try it »
Thermal Imaging of Northeastern University buildings	-	-	@evanbjacobson	-	-	0 replications: Try it »
Thermal Flashlight with LCD keypad display and Neopixel LEDs	-	-	@thosetechpeople	-	-	0 replications: Try it »
Common cathode variant of Thermal Flashlight code	-	-	@warren	-	-	0 replications: Try it »

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Activities should include a materials list, costs and a step-by-step guide to construction with photos. Learn what makes a good activity here.

Using a Thermal Flashlight

To capture the light painting over time, we have been using timelapse photography or the prototype Public Lab Thermographer website (or its inspiration, GlowDoodle), as seen in the top image on this page.

Within view of the camera or laptop, sweep the flashlight beam over the scene at a distance of about 12 inches.
Try to stay out of the way of the beam, and don't point it directly at the camera or it will create a "starburst" and may mess up your image.
It's helpful to wear dark clothing so you don't show up in the image as you're moving around.

Building your own

Parts list For a Thermal Flashlight with 3.6 V Melexis Sensor and Common Anode LED.

1 Melexis MLX90614 non-contact IR thermometer (3v). Data sheet: http://www1.futureelectronics.com/doc/MELEXIS/MLX90614ESF-DAA.pdf
1 common-anode RGB LED
2 4.7k Ohm resistors
2 100 Ohm resistors
1 180 Ohm resistor
1 0.1 μF capacitor
wire
a breadboard or circuit board & soldering eqmt.
Arduino
9v battery and holder

Software

thermal-flashlight.zip

Gist: https://gist.github.com/sdosemagen/1739961/

_Note: The goal of this file is to be a place to download everything without pursuing other links. If there are changes or updates please feel free to add and re-upload. If the file is missing anything, please comment below. You might notice that this is for the 5v Melexis, but it will work for either without issues.

Alternative variations of the Flashlight can be made with a 5.5V Melexis Sensor and Common Cathode LED. For the 5.5 V sensor follow this diagram: http://publiclaboratory.org/notes/sara/2-7-2012/circuit-diagram-5v-melexis-sensor For the common cathode circuit board follow this diagram: http://publiclaboratory.org/notes/warren/2-11-2012/common-cathode-variant-thermal-flashlight-code

Links to purchasing equipment:

Consumable Parts

LEDs (1 per flashlight, but they sell as a pack of 25): http://www.sparkfun.com/products/10818
Arduino Uno (1 per flashlight): http://www.sparkfun.com/products/11021
Capicator (1 per flashlight): http://www.sparkfun.com/products/8375
Resistor pack (this pack has a 180 ohm resistor which we found other packs not to have): http://www.eio.com/p-19326-velleman-kres-e12-pack-of-610-e12-series-resistors.aspx
3.6 V infra red thermometer (1 per flashlight): http://www.futureelectronics.com/en/technologies/semiconductors/analog/sensors/temperature/Pages/6314181-MLX90614ESF-DAA.aspx. Data sheet: http://www1.futureelectronics.com/doc/MELEXIS/MLX90614ESF-DAA.pdf

If you are starting an electronics kit from scratch:

a 40Watt soldering Iron (if you want it to be permanent otherwise duct tape or Velcro works temporarily)
hookup wire (solid not stranded- 22 or 24 gauge, you can get this at Radio Shack)
pliers called "wire strippers" to get the plastic wrap off the hookup wire (can get at Radio Shack)
solder for 40Watt iron, lead-free.
a breadboard (1 per flashlight). If you aren't soldering: http://www.adafruit.com/products/64. If you are soldering: https://www.adafruit.com/products/571.
a USB cable to connect the arduino to the computer via USB for power 5Volts (can get at Radio Shack)
household sponge for cleaning solder off tip
9 volt battery with connector wires (can get at Radio Shack- 1 per flashlight)

Cost: ~$40-$60

Updates

All research on PublicLab.org about the thermal flashlight project:

Title	Author	Updated	Likes	Comments
Can you share a link to project documentation?	@vwls	about 8 years ago	0	1
Thermal Fishing Bob Development Workshop on Northeastern's Campus	@kgrevera	over 9 years ago	2	2
Thermal Fishing Bob Development Workshop	@kgrevera	over 9 years ago	0	1
Thermal Flashlight with LCD keypad display and Neopixel LEDs	@thosetechpeople	almost 10 years ago	1	0
Common-anode LED thermal flashlight casing and circuit diagram	@lmc6399group	almost 10 years ago	4	3
dealing with patents: Black & Decker and the Thermal Flashlight	@mathew	almost 10 years ago	5	6
Finding Hotspots With Our Thermal Flashlight	@FireLogCollective	almost 10 years ago	1	0
Thermal Flashlight: Tech Failure Spectacle	@acnud	almost 10 years ago	3	4
Site Visits and Results	@KKMS	almost 10 years ago	1	1
Thermal flashlight: data collection in Holyrood, NL	@ckenny	almost 10 years ago	2	1
KKMS Thermal Flashlight Project Sociology 4107	@KKMS	almost 10 years ago	1	0
Arduino Uno Thermo Flashlight Casing Specs	@klrussell	almost 10 years ago	1	1
Comparison of Window Insulation in Old vs New buildings	@weertsc	almost 10 years ago	2	0
Thermal Imaging of Northeastern University buildings	@evanbjacobson	almost 10 years ago	1	0
Effective Cooling Methods In Refrigerators	@tapetenttm	almost 10 years ago	1	2
Thermal Imaging of Fresh Air Intake for Nightingale Hall	@jecnu	almost 10 years ago	2	0
Comparison of Heat Insulation in Two Different Aged Building using a Thermal Flashlight	@AndrewConner	almost 10 years ago	0	0
Thermal Imaging: Heat Insulation Comparison	@brachium	almost 10 years ago	1	0
Thermal imaging of Refrigerators and Milk	@williammanning	almost 10 years ago	0	0
Thermal Imaging: A Comparison of Heat Insulation	@fkamara	almost 10 years ago	0	0
Inexpensive Thermal Imaging of Decorative Lights in Household	@NoorJandali	almost 10 years ago	0	0
Thermal Imaging: Heat Insulation in Older Building	@SCG	almost 10 years ago	1	1
Thermal Flashlight Casing	@SCG	about 10 years ago	0	0
Thermal Imaging: Heat Insulation Comparison	@SCG	about 10 years ago	2	0

Several meetups have been organized to build and test thermal flashlights, at RISD (Providence, RI) and in Brooklyn, NY. We are organizing one now in Somerville, MA: